The hunt for cold - Model discussion (late November)

[northwestsnow]

2 minutes ago, Daniel Smith said:

Quite a clear and supported warming trend on the 00z GFS ensembles after the initial bout of colder air

 

I would imagine a similar story on EC ens too..

That said, i'm not bothered about that, i'm more bothered about getting the block in place, then all options are on the table imho..

As C mentioned above, UKMO 144 is far from convincing in getting the block into scandy imho.

Edited December 4, 2018 by northwestsnow

[Methuselah]

So the 00Z Para never really gets any real cold very far across the UK at all...?

Though, again, the GEFS ensemble past 11/12 (apart from a clear over all warming trend) is, relatively speaking, all over the place:

[BlueHedgehog074]

Must admit, not feeling super confident of the likely Scandinavian High Pressure that various models show lasting for long. Just feel there may be a little bit too much power to the West of the ridge to allow that to be the case. 

Off course though, should models, such as the GFS, continue to show warming events in the Stratosphere, then it does seem like the lower and upper Vortexs’ will find it hard to go on a rampage causing all sorts of grief for the cold and snow enthusiasts. And as some do bring up, a thrashed Vortex can mean more chances for High Pressure and upper ridges to establish themselves at higher latitudes to deliver cold and wintry conditions - providing they establish in suitable places. Even then, having a strong Strastospheric Vortex may not always matter as longs as both that and the Tropopause Vortex don’t work together. 

In a way, the Scandinavian ridge is still a bit far away to know for sure what it might bring as well as its duration. But some colder (and maybe wintry) weather is possible for a time from the East. It’s something I’m sure that would take some peoples’ fancy. (Even though at the same time there’s a lot of those looking for that dazzling Easterly) 

We have, however, now decided to supply buckets at the Netweather Pram Store. Just in case things don’t go to plan in the models and we end up with a scenario like the 00Z GEM. At least then, there’ll be something for you to be sick in.

[Chesil View]

5 minutes ago, Daniel Smith said:

Quite a clear and supported warming trend on the 00z GFS ensembles after the initial bout of colder air

 

I don't think any of us were expecting next week to be the beginning of a long cold spell Daniel. Just a taster for later in the month or early Jan.

[northwestsnow]

Just now, Broadmayne blizzard said:

I don't think any of us were expecting next week to be the beginning of a long cold spell Daniel. Just a taster for later in the month or early Jan.

Yes i think thats a good point..

I'm not convinced any block is going to last very long but i do believe in repeating patterns so i'm hopeful the block will be back down the line..

[Wilxy]

2 minutes ago, DiagonalRedLine said:

Must admit, not feeling super confident of the likely Scandinavian High Pressure that various models show lasting for long. Just feel there may be a little bit too much power to the West of the ridge to allow that to be the case. 

Off course though, should models, such as the GFS, continue to show warming events in the Stratosphere, then it does seem like the lower and upper Vortexs’ will find it hard to go on a rampage causing all sorts of grief for the cold and snow enthusiasts. And as some do bring up, a thrashed Vortex can mean more chances for High Pressure and upper ridges to establish themselves at higher latitudes to deliver cold and wintry conditions - providing they establish in suitable places. Even then, having a strong Strastospheric Vortex may not always matter as longs as both that and the Tropopause Vortex don’t work together. 

In a way, the Scandinavian ridge is still a bit far away to know for sure what it might bring as well as its duration. But some colder (and maybe wintry) weather is possible for a time from the East. It’s something I’m sure that would take some peoples’ fancy. (Even though at the same time there’s a lot of those looking for that dazzling Easterly) 

We have, however, now decided to supply buckets at the Netweather Pram Store. Just in case things don’t go to plan in the models and we end up with a scenario like the 00Z GEM. At least then, there’ll be something for you to be sick in.

I’ll have the red one please! In all seriousness though it’s still only the beginning of December and we are in a great position for some interest further down the line all positive from me!

[booferking]

It should be no surprise in here if the Easterly lands and produces very little majority of them never do give me a Northerly this time of year any day over an Easterly.

[Spanish Dani]

37 minutes ago, northwestsnow said:

It does look like the Azores ridge it going to make it into Scandy, after that, who knows.

EC det is lovely but there must be a helluva lot of members that push the block back before it gets chance to establish judging by the mean later on..

GEFS also look cold mid term but again a signal for the high to get shunted out of the way longerterm..

So, easterly looks fairly certain, but it might be brief..

 

 

Yes looking like milder air will come up from the South fairly quickly after an initial easterly, also Europe doesn't look very cold.

Edited December 4, 2018 by Spanish Dani

[Devonshire]

1 minute ago, Spanish Dani said:

Yes looking like milder air will come up from the South fairly quickly after an initial easterly, also Europe doesn't look very cold.

Remind me; is this thread about the hunt for cold or the extremely persistent and wide-ranging hunt for mild?!

[Weathizard]

22 minutes ago, Daniel Smith said:

Quite a clear and supported warming trend on the 00z GFS ensembles after the initial bout of colder air

 

GFS low res ensembles showing a warm up, hardly surprising considering the GFS operational tendencies of blowing away blocks the ensembles can be even more fickle. Always makes me laugh people looking for a breakdown before anything has even begun or entered a reliable timeframe.

 

 

[northwestsnow]

6Z will be interesting, as all the model run are at this time of year-  i'm not expecting a big freeze next week but i am hopeful of some seasonal weather at least..

Longer term the hope is the warmings going on up in the strat will help promote High latitude blocking highs , added to that we now have Exeter 'on board' with the last winter update really quite positive..

So, i think there is lots for coldies to be optimistic about ...

 

[Mike Poole]

Well 4/21 GEFS members have a technical SSW today, that's up from 2 yesterday.

[Methuselah]

1 minute ago, Weathizard said:

GFS low res ensembles showing a warm up, hardly surprising considering the GFS operational tendencies of blowing away blocks the ensembles can be even more fickle. Always makes me laugh people looking for a breakdown before anything has even begun or entered a reliable timeframe.

Much better we edit out all the runs that show a warming trend, eh? I think I prefer to see an ensemble, in its entirety, rather than only the cold bits. The model says what the model says...?

[Met4Cast]

7 minutes ago, Weathizard said:

GFS low res ensembles showing a warm up, hardly surprising considering the GFS operational tendencies of blowing away blocks the ensembles can be even more fickle. Always makes me laugh people looking for a breakdown before anything has even begun or entered a reliable timeframe.

 

 

Not looking for a breakdown? Just commenting on what the GEFS ensembles show. It's not like there's a massive amount of spread, every single GEFS member including the op is going for a relax in colder temperatures after the initial cold.. 

Fits in with the EPS too - initial cold then low pressure moving back in from the Atlantic as blocking relaxes/moves too far North-East.

Extended EPS moves the Atlantic trough through the UK and has it to the East by day 15, so certainly not a "mild" pattern.

Edited December 4, 2018 by Daniel Smith

[SLEETY]

2 minutes ago, Weathizard said:

GFS low res ensembles showing a warm up, hardly surprising considering the GFS operational tendencies of blowing away blocks the ensembles can be even more fickle. Always makes me laugh people looking for a breakdown before anything has even begun or entered a reliable timeframe.

 

 

Happens all the time in the winter months.Dont even know yet if we will get  a proper easterly,nothing in the reliable time frame,yet  but people talk about the end of the cold spell already  

As for the gfs it’s been all over the place,yesterday it wasn’t interested in any easterly,so why should we believe anything it shows especially longer term,and ensembles always flip flop and run at a lower resolution.METO never use them from what I have heard before.

[northwestsnow]

2 minutes ago, Mike Poole said:

Well 4/21 GEFS members have a technical SSW today, that's up from 2 yesterday.

Yes that paints a pretty picture.. even if we dont get a technical SSW the drop in zonal winds will do us no harm.

[Rayth]

3 minutes ago, Mike Poole said:

Well 4/21 GEFS members have a technical SSW today, that's up from 2 yesterday.

Oooo a nice 19.05% looks better on the eye than 4/21 mike ... could be 6 tomorrow (28.5 %) or gone completely , let’s hope for the trend  

[northwestsnow]

3 minutes ago, Daniel Smith said:

Not looking for a breakdown? Just commenting on what the GEFS ensembles show. It's not like there's a massive amount of spread, every single GEFS member including the op is going for a relax in colder temperatures after the initial cold.. 

Fits in with the EPS too - initial cold then low pressure moving back in from the Atlantic as blocking relaxes/moves too far North-East.

Extended EPS moves the Atlantic trough through the UK and has it to the East by day 15, so certainly not a "mild" pattern.

I think the last line is quite important actually, while the block may not sustain, the hope is it has enough 'effect' on the jet to steer the lows on a SE trajectory...

Thats kind of what im hoping for..

[northwestsnow]

TBH when looking at 6z at T48 you'd be hard pressed to think an easterly is even a remote chance!

Icelandic low, Euro heights,no HL block anywhere near the UK..

Could be one for Weather historys 'where did that easterly come from' archive..

[feb1991blizzard]

10 minutes ago, Mike Poole said:

Well 4/21 GEFS members have a technical SSW today, that's up from 2 yesterday.

That really is a telling graph, if that downward trend continues  for say another few days, baring in mind the accuracy at 70000ft is massively greater than at 0-18000ft, then we will past the point of return in terms of severe early season (possibly irreversible) damage to the stratospheric polar vortex.

[Glacier Point]

EC 45 dayer shows marked drop in AO forecast second week of January to -2SD (mean), commencing in trend 26th December. Wonder what's driving that then ? Consistency with GLOSEA on stratospheric forecast.

NAO forecasts not as negative, but worth pointing out that a Scandinavian block is not well represented within that index. FWIW, thinking would be for the NAO to move in concert with the AO here as pressure will likely be anomalously low in the Atlantic.

[Met4Cast]

9 minutes ago, SLEETY said:

Happens all the time in the winter months.Dont even know yet if we will get  a proper easterly,nothing in the reliable time frame,yet  but people talk about the end of the cold spell already  

As for the gfs it’s been all over the place,yesterday it wasn’t interested in any easterly,so why should we believe anything it shows especially longer term,and ensembles always flip flop and run at a lower resolution.METO never use them from what I have heard before.

To be fair the Met Office have UKMO and MOGREPS, I believe they use those in conjunction with the EPS. 

Given we don't have access to two of those, we don't really have much choice but to go with the GFS Ensembles. MOGREPS could be showing something similar for all we know.

EPS relax the cold similar to the GFS, initial blocking too far NE on the 00z EPS and this allows the Atlantic to move in post 240, though it's certainly not a mild zonal pattern, more cold zonal if anything.

[northwestsnow]

Just now, feb1991blizzard said:

That really is a telling graph, if that downward trend continues  for say another few days, baring in mind the accuracy at 70000ft is massively greater than at 0-18000ft, then we will past the point of return in terms of severe early season (possibly irreversible) damage to the stratospheric polar vortex.

Absolutely Feb

Events up in the strat coupled with Exeters flip to colder than average winter -(Octobers was for above average)leads me to believe Glosea5 is seeing a very weak PV this winter..

ALWAYS good news , not a guarantee of cold weather for the UK of course, but certainly beats a rampant PV every day of the week!

[northwestsnow]

1 minute ago, Glacier Point said:

EC 45 dayer shows marked drop in AO forecast second week of January to -2SD (mean), commencing in trend 26th December. Wonder what's driving that then ? Consistency with GLOSEA on stratospheric forecast.

NAO forecasts not as negative, but worth pointing out that a Scandinavian block is not well represented within that index. FWIW, thinking would be for the NAO to move in concert with the AO here as pressure will likely be anomalously low in the Atlantic.

Blimey i  just posted  about the same thing as you did Stewart -

The Scandy high could be a player this Winter..

Not too bothered about an Active Atlantic if we have a block to the NE, esp with a block to the NE re-enforced by a disturbed PV..

[Stormyking]

Very interesting charts again this Morning, ECM sticking with its idea, UKMO looks like it would be very decent if there were any runs after 144 and the GFS also looking very nice for the cold and Scandi high potential!

Hopefully the 6z can continue